Neobook leaves me the choice of the file extension.
And it does not extend itself.
In my case, I have chosen the extension dbt.
But if I try to define this file in report designer, it does not connect.
He asked absolutely a file with the extension. MDB

However, this is not important, I will use the extension mdb.
I saw there a way to "protect" the file with a double-click, which would open in another program that my publication.

For Neosoft Support:
I feel that every message I post is "against" NeobookDBPro.
Do not look at the "harcellement."
I said that every situation that users encounter, can help to further improve this beautiful work that Neobook
In any case, thanks for your help.

NeoBookDBPro uses the file extension to identify the type of database you're using, so changing the file extension may have unintended consequences. To prevent the file from being edited by another application, you can use the dbpCreateAccessDatabase action to create a password protected database. Then use dbpOpenAccessDatabase to open the protected file.

For Neosoft Support: I feel that every message I post is "against" NeobookDBPro. Do not look at the "harcellement." I said that every situation that users encounter, can help to further improve this beautiful work that Neobook In any case, thanks for your help.

That's OK. No software is perfect, and this forum's purpose is to answer questions, solve problems and promote NeoBook.